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Subject: Excerpt Of History
Date: Wed, 19 Jan 2005 18:11:47 EST
Henry Bessemer
(http://en.wikipedia.org/wiki/Image:Henry_Bessemer.jpg)
Sir Henry Bessemer (January 19, 1813 - March 15, 1898), English engineer,
was born at Charlton near Hitchin in Hertfordshire.
Throughout his life, he was a prolific inventor, but his name is chiefly
known in connection with the Bessemer process for the manufacture of steel.
Though this process is now largely supplemented, and even displaced, by various
rivals, at the time of its invention it was of enormous industrial importance
because it lowered the cost of production of steel, leading to that material
being widely substituted for others which were inferior in almost every
respect but that of cost. Bessemer's attention was drawn to the problem of steel
manufacture in the course of an attempt to improve the construction of guns.
Coming to the conclusion that if any advance was to be made in artillery better
metal must be available, he established a small ironworks in St Pancras, and
began a series of experiments. These he carried on for two years before he
evolved the essential idea of his process, which is the decarbonization of
cast iron by forcing a blast of air through the mass of metal when in the molten
condition. The first public announcement of the process was made at the
Cheltenham meeting of the British Association in 1856, and immediately attracted
considerable notice. Many metallurgists were sceptical on theoretical grounds
about his results, and only became convinced when they saw that his process
was really able to convert melted cast iron into malleable iron in a
perfectly fluid state.
But though five firms applied without delay for licences to work under his
patents, success did not at once attend his efforts; indeed, after several
ironmasters had put the process to practical trial and failed to get good
results, it was in danger of being thrust aside and entirely forgotten. Its author,
however, instead of being discouraged by this lack of success, continued his
experiments, and in two years was able to turn out a product, the quality of
which was not inferior to that yielded by the older methods. But when he now
tried to induce makers to take up his improved system, he met with general
rebuffs, and finally was driven to undertake the exploitation of the process
himself. To this end he erected steelworks in Sheffield, on ground purchased
with the help of friends, and began to manufacture steel. At first the output
was insignificant, but gradually the magnitude of the operations was enlarged
until the competition became effective, and steel traders generally became
aware that the firm of Henry Bessemer & Co. was underselling them to the extent
of £20 a ton. This argument to the pocket quickly had its effect, and
licences were applied for in such numbers that, in royalties for the use of his
process, Bessemer received a sum in all considerably exceeding a million pound
sterling. (Sheffield's Kelham Island Industrial Heritage Museum, maintains an
early example of a Bessemer Converter for public viewing).
Of course, patents of such obvious value did not escape criticism, and
invalidity was freely urged against them on various grounds. But Bessemer was
fortunate enough to maintain them intact without litigation, though he found it
advisable to buy up the rights of one patentee, while in another case he was
freed from anxiety by the patent being allowed to lapse in 1859 through
non-payment of fees. At the outset he had found great difficulty in making steel by
his process; in his first licences to the trade iron alone was mentioned.
Experiments he made with South Wales iron were failures because the product was
devoid of malleability; Mr Goransson, a Swedish ironmaster, using the purer
charcoal pig iron of that country, was the first to make good steel by the
process, and even he was successful only after many attempts. His results
prompted Bessemer to try the purer iron, obtained from Cumberland haematite, but
even with this he did not meet with much success, until Robert Mushet showed
that the addition of a certain quantity of spiegeleisen had the effect of
removing the difficulties.
Whether or not Mushet's patents could have been sustained, the value of his
procedure was shown by its general adoption in conjunction with the Bessemer
method of conversion. At the same time it is only fair to say that whatever
may have been the conveniences of Mushet's plan, it was not absolutely
essential; this Bessemer proved in 1865, by exhibiting a series of samples of steel
made by his own process alone. The pecuniary rewards of Bessemer's great
invention came to him with comparative quickness; but it was not till 1879 that
the Royal Society admitted him as a fellow and the government honoured him with
a knighthood. Bessemer died at Denmark Hill, London.
Among Bessemer's numerous other inventions, not one of which attained a tithe
of the success or importance of the steel process, were movable dies for
embossed stamps, a gold paint, sugar machinery, and a ship which was to save her
passengers from the miseries of mal de mer. This last had her saloon
mounted in such a way as to be free to swing relatively to the boat herself, and
the idea was that this saloon should always be maintained steady and level, no
matter how rough the sea. For this purpose hydraulic mechanism of Bessemer's
design was arranged under the control of an attendant, whose duty it was to
keep watch on a spirit-level, and counteract by proper manipulation of the
apparatus any deviation from the horizontal that might manifest itself on the
floor of the saloon owing to the rolling of the vessel. A boat, called the
Bessemer, was built on this plan in 1875 and put on the cross-Channel service to
Calais, but the mechanism of the swinging saloon was not found effective in
practice and was ultimately removed.
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